- In a series of consecutive trials using this chemotherapy preparative regimen alone or with 2 Gy or 12 Gy total body irradiation (TBI) objective response rates using RECIST criteria were 49%, 52%, and 72%, respectively. Complete regression rates in these three consecutive trials were 12%, 20%, and 40%, respectively strongly suggesting that the addition of TBI could improve the complete regression rate. Of the 20 complete regressions seen in this trial, 19 are on-going at 37 to 82 months.